Hamilton Beach FlexBrew (Trio) vs Keurig K-Duo

This is our Hamilton Beach FlexBrew Trio vs Keurig K-Duo comparison guide.

The Hamilton Beach FlexBrew Trio and Keurig K-Duo are some of the most versatile brewers on the market. Combining the ease of a carafe brewer with the convenience of single-cup brewing, these machines have something to satisfy anyone. 

We have spent many hours reading, and talking to experts to be able to offer the best comparison guide between these two coffee makers.

At first glance, these machines may seem very similar. They both offer dual brewing, have similar profiles, and boast similar prices. 

But, which one is better? Keep reading to find out.

Overview: Hamilton Beach FlexBrew Trio vs Keurig K-Duo

Hamilton Beach FlexBrew

Hamilton Beach
FlexBrew Trio

Keurig K-Duo

Keurig K-Duo

This is a lengthy comparison between the Keurig K-Duo vs the Hamilton Beach FlexBrew Trio: as such, before we dive into things, let’s go over the basic differences between these two machines.

While they may seem very similar at first glance, they actually differ greatly in everyday use.

Firstly, the Hamilton Beach FlexBrew Trio operates on a pour-as-you-go model, which means that however much water you put in will be the size of the cup of coffee. 

The Keurig K-Duo brews cups of coffee, but in this case, you can actually select the brew size each time.

Secondly, the Hamilton Beach FlexBrew is dishwasher safe, whereas the K-Duo is not. This helps save you time in the cleaning process. 

Both of these machines have auto-off features, and will automatically pause brewing if the carafe is removed. Below, we go more into depth about the key features of each of these coffee makers.

Here’s an introductory video of the Hamilton Beach FlexBrew.

Here’s an introductory video of the Keurig K-Duo.

Comparison Table

SpecificationsHamilton Beach FlexBrew TrioKeurig K-Duo
Brew SizesUp to 10oz (K-Cup), 14oz (ground coffee), and 12 cups in carafe (ground coffee)6, 8, 10, or 12-cup carafe and a 6oz, 8oz, 10oz, or 12oz cup
Water Tank CapacitySingle-cup (14oz approx), carafe (60oz approx)60oz
Removable Water Reservoir✔️
Water Filter Compatibility✔️
Product Dimensions13.7″ (18″ when open) H x 12.2″ W x 11.4″ D12.9″ (17.6” when open) H x 10.9″ W x 12.7″ D
ColorsBlack, WhiteBlack, Silver
Strength Controls✔️✔️
Travel Mug Friendly✔️✔️
Hot Water On Demand✔️✔️
Auto Brew (Scheduled Brew)✔️✔️
Auto Pause and Pour✔️✔️
Heating Plate✔️✔️
Cord Storage✔️

Key Features: Keurig K-Duo vs Hamilton Beach FlexBrew Trio

Here, we dive into the key features regarding the Hamilton Beach FlexBrew Trio vs Keurig K-Duo. 

Brew Sizes

The Hamilton Beach FlexBrew brews both single cups of coffee, and carafe coffee. For single size cups, you can brew up to 14 ounces at once, if using ground coffee, or up to 10 ounces when using a K-Cup. 

The FlexBrew is also able to brew up to 12 cups of coffee in a carafe.

The Hamilton Beach FlexBrew has a separate water reservoir for single cup brewing and carafe brewing.

Both types of brewing use all the water in the reservoir during a brew cycle, meaning however much water you pour into the reservoir will be the amount of coffee that comes out.

This can be beneficial, because it gives you greater control over the size of your cup of coffee, but it can also be a hindrance, as you have to refill the machine before every brew cycle. 

Alternatively, the Keurig K-Duo has one water reservoir for both single cup and carafe brewing. 

You can brew single cups of coffee in 6, 8, 10, or 12 ounce sizes. Carafe brewing allows you to choose between 6, 8, 10, or 12-cup servings

While you do gain the convenience of not having to fill the water reservoir before every brew cycle, you do lose some of the fine tuning and extra customization gained with the Hamilton Beach FlexBrew. 

Winner: Hamilton Beach FlexBrew Trio

Water Reservoir

As we said earlier, the Hamilton Beach FlexBrew has two separate water reservoirs, one for single cup brewing and the other for carafe brewing. 

These water reservoirs are non-removable, and do not hold water between brewing cycles. All the water in the reservoir is used during the brew.

The single-cup water reservoir holds up to 14 ounces of water, and the carafe tank holds up to 12 cups (about 60 ounces).

Additionally, both water reservoirs have see-through indicators showing how much water is in the reservoir. 

The Keurig K-Duo has one removable 60-ounce water reservoir. The K-Duo’s reservoir does hold water between brew cycles, and brew sizing is selected through the button interface on the machine, rather than the amount of water you pour into the reservoir.

We consider the Keurig K-Duo’s tank to be more convenient as it can be removed for easier cleaning and refilling.

Winner: Keurig K-Duo

Ease of Use

Both Keurig and Hamilton Beach machines are known for their ease of use.

The Hamilton Beach FlexBrew has a simple, straightforward layout, with buttons to brew a single cup, carafe, adjust brew strength, set time, and program automatic brewing. 

Using the machine is a pleasure, and extremely easy.

The Keurig K-Duo also has a straightforward button layout, with buttons for single cup brewing, carafe brewing, brew strength, and auto-brew.

As the button layouts and usability are extremely similar, these machines are tied in this area.

Below you will find the official manuals of these machines:

Winner: Tie

Brew Quality and Performance

The FlexBrew heats up the water before actually brewing, and is not the fastest around. It takes around 2 to 3 minutes to brew a 10oz cup of coffee. The coffee comes out at around 175°F after brewing. 

For carafe brewing, it takes approximately one minute per cup to brew, so if you’re brewing a full pot (12 cups), it will take about 12 minutes. Immediately after pouring the coffee, it sits at around 168°F. 

The K-Duo takes approximately 1 minute to brew an 8oz cup of coffee. The coffee immediately after brewing sits at around 165°F. 

For carafe brewing, it takes approximately 1 minute per cup, and the temperature was over 167°F. Very similar to the FlexBrew.

Both machines brew excellent coffee, however, it seems that the K-Duo is a little bit faster when brewing single-serve coffee, but the FlexBrew produces hotter single-serve coffee. Therefore, the decision will depend on your preferred advantage.

Winner: Tie

Capsule and Grounds Compatibility

Both the Keurig K-Duo and the Hamilton Beach FlexBrew are compatible with K-Cups and any ground coffee

When brewing a carafe using ground coffee, a coffee filter is needed.

For both machines, only ground coffee can be used to brew a carafe.

For single cups of coffee, both K-Cups and ground coffee can be used, however, the K-Duo needs a reusable coffee filter since it doesn’t come included with a single cup basket for coffee grounds. The FlexBrew does.

Since the FlexBrew doesn’t need an additional reusable K-Cup coffee filter, we consider it the most convenient model. (You can still buy the K-Duo and a reusable K-Cup coffee filter if you really like it).

Winner: Hamilton Beach FlexBrew Trio

Cleaning and Maintenance

Both of these machines are easy to keep clean – and regular maintenance can help your machine last longer.

General Cleaning

Both of these machines benefit greatly from regular wiping down, in order to minimize smudges, stains, and fingerprints, to keep them looking their best.

The drip tray should be emptied and washed regularly, to prevent overflow, and rinsing out the water tank can help reduce the potential for mold or mildew. 

All of the components of the Hamilton Beach FlexBrew are dishwasher safe, while the components of the K-Duo are not.

Disclaimer: Avoid using the SANI setting when washing the parts of your FlexBrew in the dishwasher since you can damage the parts this way.

Keurig K-Duo Official Cleaning Guide
Keurig K-Duo Cleaning Guide – Source: Keurig K-Duo Manual


Descaling on both of these machines follows a standard procedure. Check out the videos below for detailed how-tos.

Hamilton Beach FlexBrew:

Keurig K-Duo:

Which One Is Easier to Clean?

Since the FlexBrew has two separate water tanks, it can be more annoying and time-consuming to clean, that’s why we consider the K-Duo more convenient in terms of cleaning, but there are no major differences apart from that.

Winner: Keurig K-Duo

Design, Dimensions, and Weight

These coffee makers are very similar in terms of design, size, and weight.

Dimensions and weight of the Hamilton Beach FlexBrew Trio:

  • Height: 13.7″  (18″ when open)
  • Width: 12.2″
  • Depth: 11.4″
  • Weight: 11.6lbs

Dimensions and weight of the Keurig K-Duo:

  • Height: 12.9″ (17.6” when open)
  • Width: 10.9″
  • Depth: 12.7″
  • Weight: 9.7lbs

With these specifications, we can see that the Hamilton Beach FlexBrew’s dimensions are a little bit larger.

In terms of design, the FlexBrew and the K-Duo look very similar, with the main differences being the display and button layout.

On the FlexBrew, the display and buttons are on the front of the machine, while they’re on top of the K-Duo. The K-Duo looks cleaner, with its smooth edges and more flush single brew section. 

These are the colors available for the FlexBrew Trio:

  • Black
  • White

These are the colors available for the K-Duo:

  • Black
  • Silver

You can buy a version of the FlexBrew with a glass carafe, and a version with a thermal carafe. The thermal carafe keeps the coffee hot for longer periods of time, which is nice if you drink coffee throughout the day. 

As you can see, the differences in the design of these two machines are very subtle, the major difference is that the FlexBrew is a little bit larger, however, in the end, it really comes down to personal preferences.

Therefore, it is difficult to say which one is better, and we deem these machines tied in this area.

Winner: Tie

Additional Features

There are a few additional features that these machines have that separate them from each other, and other machines on the market as a whole. 

Auto Off

Both of these machines have an auto-off feature, which is awesome for saving energy. While they both have this feature, their implementation varies a little. 

On the Hamilton Beach FlexBrew, the machine will automatically shut off two hours after the last brew. 

On the Keurig K-Duo, the heating plate will automatically shut off two hours after the last brew and the machine will automatically turn off five minutes after the last single brew. 

Travel Mug Friendly

Both the Keurig K-Duo and Hamilton Beach FlexBrew are compatible with travel mugs.

  • The Hamilton Beach can accommodate mugs up to 7” tall. 
  • The K-Duo works with travel mugs up to 8” tall.

Hot Water on Demand

Both of these machines support hot water on demand. 

To pull hot water on demand from either, you can simply follow a normal brewing cycle on the single-serve side, just without any ground coffee or K-Cup in place.

Auto Brew (Scheduled Brew)

Auto-brew is an incredible feature to have on a coffee maker because it allows you to wake up every morning to a fresh, piping hot pot of coffee. 

On the Hamilton Beach FlexBrew, you can set carafe auto-brewing by holding down the program button, and then pressing the time button to set brew time. You can also choose between regular and bold brewing. 

The K-Duo also supports auto-brewing, and works by pressing the program button, and then adjusting the settings to your tastes. 

It is important to note that, on both these machines, auto-brewing only works with carafe brewing.

Auto Pause and Pour

Both of these machines have an auto pause and pour feature. This means that you can pull the carafe out and pour coffee during the middle of a brew, and the machine will pause brewing for 20 seconds, and then resume.

Warning: If you pause the brewing process for more than 20 seconds it may cause the coffee to overflow from the filter basket.

This is extremely nice because it allows you to pour a cup of coffee before the entire brew cycle is complete, and is a must-have for any of us coffee fiends.

Heating Plate

Both of these machines have heating plates.

On the Hamilton Beach FlexBrew, the heating plate automatically turns on after a brew cycle, and stays on for two hours. To reactivate it, you have to run another brew cycle or simply turn the machine on.

On the Keurig K-Duo, the heating plate also stays on for two hours after completing a brew cycle, by default. However, you can toggle the warming plate on and off by pressing and holding the carafe button for around three seconds.

Cord and Brewing Basket Storage

On the Hamilton Beach FlexBrew, there are built-in storage compartments for the cord and the single-serve brewing basket. This is great for people with limited storage options or traveling. 

There are no equivalent storage options for the Keurig K-Duo. 

Which Coffee Maker Has the Best Additional Features?

These two machines are very similar when it comes to their additional features, with both machines boasting things like programmable brewing, auto-off features, and pause and pour. 

Winner: Tie

Pros and Cons

There are a few pros and cons of each of these machines that are worth considering when deciding which one is right for you.

Hamilton Beach FlexBrew Trio Pros and Cons

Pros and cons of the Hamilton Beach FlexBrew Trio.


  • More customization over brew size
  • Built-in storage for cord and brew basket
  • Strength settings
  • Parts are dishwasher safe
  • Programmable


  • You have to refill the water tank before every brew
  • It takes a long time to brew

Keurig K-Duo Pros and Cons


  • You don’t have to refill the water tank before every brew
  • Strength settings
  • Modern design
  • Programmable


  • Not dishwasher safe
  • No cord and brew basket storage compartments


Both of these machines are excellent options for people looking for simple, versatile brewers. However, if you’ve read through this review and think you need something different, here are a few alternatives.

Ninja DualBrew Pro

Ninja DualBrew Pro
  • Key Feature: Built-In, fold-away frother
  • Brew Sizes: 6oz, 8oz, 10oz, 12oz, and 12-cup carafe
  • Water Reservoir: 60oz
  • Material: Plastic
  • Brand: Ninja

The Ninja DualBrew Pro is a fantastic machine from Ninja that looks great and has enough brew methods and features to satisfy even the most avid coffee drinker. 

Boasting four different brew types, the Ninja DualBrew Pro is one of the most versatile machines in its class.

These include Classic, Rich, Over-Ice, and Specialty. You can brew coffee in small Cup, Cup, XL Cup, Travel Mug, XL Travel Mug, ¼ Carafe, ½ Carafe, ¾ Carafe, or Full carafe sizes. 

Unlike the Hamilton Beach FlexBrew and Keurig K-Duo, the Ninja DualBrew brews an espresso-like concentrate, their “Special” setting. This is perfect for making drinks like cappuccinos, lattes, and macchiatos. 

Speaking of specialty drinks, the machine has a built-in foldaway steam wand for frothing milk and making foam. This makes cappuccinos, lattes, and more a breeze.

The DualBrew Pro looks fantastic, and its usability is top-notch. The machine comes with very easy-to-use controls for changing settings and customizing all aspects of your brew. 

If you’re looking for a machine that looks great and makes all kinds of coffee drinks, the Ninja DualBrew Pro deserves a long look.

Cuisinart Coffee Center

Cuisinart Coffee Center
  • Key Feature: Adjustable carafe temperature
  • Brew Sizes: 6oz, 8oz, 10oz, and 12-cup carafe
  • Water Reservoir: 40oz
  • Material: Stainless steel, plastic
  • Brand: Cuisinart

The Cuisinart Coffee Center is a great machine for those who value a premium build and versatility. 

The Cuisinart Coffee Center allows you to brew both single cups of coffee, in 6-ounces, 8-ounce, and 10-ounce sizes, and carafe coffee. For carafe brewing, your brew size is however much water you pour in. 

Single-serve brewing can be done using both regular ground coffee, through their single-serve basket, or through the use of pods.

The machine has many thoughtful features that make it a pleasure to use. These include programmable brew settings, a strong brew mode, adjustable auto-off, pause and pour, and self-cleaning.

Self-cleaning, in particular, is a fantastic feature to have because it reduces mineral buildup in the machine, helping it last longer. Self-cleaning also saves you time. 

The Coffee Center is made of plastic and metal, and looks and feels fantastic. 

All in all, this is a great machine for those who value convenience, usability, and design.

The Bottom Line: Keurig K-Duo vs Hamilton Beach FlexBrew Trio

At this point of our Hamilton Beach FlexBrew Trio vs Keurig K-Duo comparison guide, you should already know which one is better for you, right?

No? Well, both of these machines are convenient, extremely versatile, and come from quality brand name manufacturers. They both work well, and brew excellent coffee. 

However, the slightly better coffee quality, paired with the greater ability to fine tune brew size, the more convenient storage options, and the lower price just made the Hamilton Beach FlexBrew Trio more compelling to use

That isn’t to say that the K-Duo is a bad machine; far from it. It brews great coffee, looks wonderful, and integrates well with other Keurig products. We just think that the FlexBrew is a little better. 

If you really liked the K-Duo, but want another alternative than the Hamilton Beach, you can check the K-Duo Essentials.

FAQ – Hamilton Beach FlexBrew Trio vs Keurig K-Duo

Wanna learn more about the differences between the Keurig K-Duo vs the Hamilton Beach FlexBrew? Check the FAQs below.

Is Hamilton Beach Coffee Maker Better Than Keurig?

Both Hamilton Beach and Keurig make great convenient coffee makers for the general public. While we liked the FlexBrew more than the K-Duo, we can’t say that all Hamilton Beach machines are better than Keurigs.

Does Hamilton Beach FlexBrew Trio Use Keurig Cups?

Yes; the Hamilton Beach FlexBrew can brew single-cups of coffee using either K-Cups, or ground coffee.

Is the Keurig Duo Plus Worth It? 

That depends; the K-Duo Plus has a much slimmer design, with many of the same features as the K-Duo. In fact, we prefer the K-Due Plus over the K-Duo for its convenient design.

Leandro Santorsola
Leandro Santorsola

Leandro is the founder of The Coffee Arsenal. His favorite relaxation method is to drink a Cafe Latte in the afternoons.